Transdermal drug delivery is a well known method for administering pharmaceuticals. The potential for abuse of certain pharmaceuticals, such as narcotics and other psychoactive drugs, is also well known. It is thus desirable when preparing a transdermal dosage form containing a substance with the potential for abuse to make such a device resistant to abuse or misuse. Although a transdermal dosage form is intended to deliver drug across the skin, misuse or abuse of such a dosage can take place by other modes, including oral, buccal, and intravenous.
Transdermal dosage forms comprising both a drug and an antagonist for the drug have been previously proposed. U.S. Pat. No. 5,236,714 (Lee et al.) describes a transdermal dosage form which comprises a mixture of a drug and an antagonist for the drug. U.S. Pat. No. 5,149,538 (Granger, et al.) describes a transdermal dosage form comprising an opioid permeable to the skin, an antagonist for the opioid releasable upon ingestion or solvent immersion of the dosage form, and an impermeable barrier means separating the opioid and the antagonist.